This invention relates generally to navigation equipment and particularly to equipment for conning a ship at night, especially during plane-guard operations in which a ship follows an aircraft carrier at a selected distance. In addition, this invention can be used for any land, sea, or air navigation where a person or vehicle moves to a specific location.
Operating a surface combatant at night in close proximity to an aircraft carrier can be one of the most challenging and dangerous tasks at sea. During a plane guard task for example, an aircraft carrier is launching and recovering aircraft while the surface combatant is positioned a few thousand yards astern of the aircraft carrier. The surface combatant""s conning officer""s attention is divided between gauging the location of the aircraft carrier, monitoring aircraft traffic, searching the water for other vessels, and avoiding foreign obstacles. To accomplish these tasks, the combatant""s conning officer must estimate the aircraft carrier""s distance and bearing by visual and auditory information; however, in certain situations these cues may be ambiguous which may lead to a loss of situational awareness by the conning officer.
For centuries, sailors used navigation aids, such as flags, smoke and lights, to signal and maneuver around ships and other obstacles. Early navigation aids date back to the Roman era, around 300 B.C., when lighthouses built near the mouth of the Nile were used to guide ships and assist with coastal navigation. During the U-boat battles of World War I, convoys of 20 or more supply ships would transit the Atlantic Ocean in tight-knit packs at ranges as close as 750 yards. Radar had not yet been developed, so the conning officer viewed red and white lights mounted on the vessel to maintain a safe distance between ships. When engaging the enemy, British destroyers illuminated two red lamps spaced two meters apart horizontally on the port yardarm, and two green lamps on the starboard yardarm. Ocean vessels of today are equipped with advanced navigation systems such as radar, global positioning system, and automatic pilot systems to enhance conning officers"" situational awareness. Despite these advanced navigation systems collisions between surface vessels still occur. Typically a collision occurs after a ship""s crew loses situational awareness of the surrounding area.
The present invention comprises a Tactical Vectoring Equipment (TVE) that includes a plurality of lights mounted on the stem of the aircraft carrier for assisting shipboard conning officers when maneuvering in a battle group formation.
The tactical vectoring Equipment preferably comprises six red and green lights mounted on the stem of an aircraft carrier. The lights are preferably arranged in a linear array with the lights being spaced approximately six to nine feet apart. The lights are clearly visible to a conning officer on an escort ship while being invisible to the carrier pilots during flight operations such as landing or approaching the flight deck. The lights are arranged such that the number of red and green lights seen from an escort ship that is astern the aircraft carrier depends on the angular orientation of the vector between the escort ship and the aircraft carrier. The red and green light configuration of the tactical vectoring Equipment enables the conning officer to easily discriminate range and bearing of the stern of the aircraft carrier in relation to the escort ship, thereby providing increased situational awareness for conning officers during battle group formations.
Accordingly, it is an object of this invention to provide an improved navigation device for maritime operations.
It is another object of this invention to improve training of maritime conning officers. Most conning officers spend many hours on watch in order to develop an accurate understanding of how a ship turns and maneuvers. This is because, for the most part, they are guessing how a carrier will turn and react at different speeds. Through trial and error, and under the careful guidance of their commanding officers, conning officers will eventually develop a sense of the relative motion between ships. The present invention provides an immediate indication of how the ship is turning and the characteristics of the turn. For example, the faster the TVE lights change colors, the faster the carrier is turning. This gives the conning officer an immediate visual indication of the carrier""s advance/transfer rates and its effect on relative position. Thus, the TVE is a useful training aid that can develop and improve a junior naval officer""s ship-handling skills more quickly.
It is another object of this invention to provide feedback to the conning officer of the escort ship when the lead ship reverses course. When a backing engine is ordered (throttles in the backing position on the ship""s control console), a relay circuit temporally modulates the TVE lights in unison. This provides an immediate warning signal to the escort ship""s conning officer that the carrier is backing, decreasing speed more rapidly, and may actually transit backwards.
It is another object of this invention to aid restricted emission control (EMCON) operations. During battle conditions and mission requirements that restrict the use of ship""s radar and line-of-sight communications systems, the TVE could still operate. The lights have a specified vertical arc of visibility to prevent interference with pilots. The TVE can be seen for only a few miles at sea level and preferably is restricted vertically to less than one degree above the horizon in order to support operation with the carrier""s aircraft.
It is another object of this invention to provide visual guidance for maritime column formation, underway replenishment, and any other application where two or more surface vessels need to rendezvous, follow each other, change course, or depart formation.
It is another object of this invention to estimate range to another vessel without the use of radar. A common technique used by mariners involves using a set of binoculars and a ship""s dimensions to determine range. At a given range, binoculars have a set field of view (FOV) across the lens. For example, a standard set of binoculars (7xc3x9750) at a range of 1,000 yards has an FOV of 360 feet. This means that an object having a length of 45 feet would fill one-eighth of the binocular lens. At 500 yards the FOV is 180 feet. The same object having a length of 45 feet now fills one-quarter of the binocular lens. Using this example, if the lights are positioned nine feet apart, then total length of the TVE array is 45 feet. An approximate distance to the vessel can now be determined by applying this principal. This provides immediate bearing and range information to the conning officer, improving his ability to accurately form a mental picture of the carrier""s heading and target angle.
It is another object of this invention to provide visual land guidance to traverse from one location to the next. The TVE could direct a vehicle to a desired location, e.g., an aircraft could follow the TVE lights to a designated point on the airport surface.
It is another object of this invention to provide precise navigation guidance by changing the spacing between the lights and the distribution of red and green lights within a light unit. Furthermore, the two colors selected for the TVE do not have to be red or green.